A standard fuel-injection nozzle for an internal-combustion engine has a nozzle body formed with a bore in turn formed with a valve seat centered on an axis and tapered axially in a fuel-flow direction. This seat has relative to the direction an annular downstream edge. An axially displaceable valve needle has a surface engageable with and complementary to the seat and is formed with a throttle pin normally projecting axially into the bore past the seat edge. This needle lifts against the flow of fuel through the nozzle off the seat to permit the fuel to flow to the respective cylinder of the engine.
Such injection nozzles of this generic type have the advantage that the throughput cross section in the nozzle bore hole, which throughput cross section is formed by means of a flattened portion at the throttle pin, tends to gum up less than an annular gap between a fully cylindrical throttle pin and the nozzle bore. In a known injection nozzle of the generic type mentioned in German patent document No. 3,326,468 the flattened portion at the throttle pin is arranged so as to be inclined relative to the nozzle axis, so that the desired effect of an increasing pass-through cross section is produced until the emergence of the throttle pin from the nozzle bore. However, it is difficult to maintain the prescribed angular position of such a flattened portion in industrial-scale production and it can only be checked at increased cost, since the reference points must be maintained with extreme accuracy.